to hide the cables, just secure your probe where you want it, and run the cable under the substrate to one of the back corners.
Then run it up along the corner, and put your lid over the top of the tank.

The lid will keep the cable tight enough not to dangle loosely around.

Also, if you plan on keeping that thermometer/thermostat and tank, you could always use non-toxic silicone, the same kind used to 'stick' the class panels together to make the tank, and just silicone the cord up along the joining of the back and side panel.

Then, just put a fake plant in that corner, or black backing for the sides and back, and you wont even know it's there, neither will your snake.

Or, if for some reason your lid wont fit with the cable over the top, you can make a small cutout at the very top of the tank, just big enough for the cable to rest in, and be level/slightly lower than the tank top, then the lid will fit perfectly. But make sure the tank is EMPTY if you do that, you dont want glass shards over your substrate. When it's done, clean the tank out nicely, and put everything back in.